| Exhaust tuning is very simple.
Hot gas at combustion pressure will pass through any exhaust port into any exhaust pipe really easily, but the faster the better to reduce heat transfer into the engine.
When it is in the pipe, getting it out the other end is not a real problem by itself, cos its hot and expanding, so any size pipe will do.
Its the sound pressure waves that have to be managed in the pipe - and you simply have to choose what frequency you are going to tune for ie what engine revs you want to optimise.
You then work out the exhaust volume you need in order to get the returning pressure wave keeping the fresh change in the cylinder at that rpm.
You then simply lay out the plumbing.
So, if you want high rpm power, you need a high volume exhaust, and if you want low rpm power, you need a low volume exhaust.
Engine tuners have been doing this for almost 100 years.
Go get a copy of 'Tuning for speed' by Phil Irving. |